THz Waves: Fast Lane Journey to 6G
22 April 2021
Organizer: Angeliki Alexiou, University of Piraeus, email@example.com
Motivation, Background and Scope
While the wireless world is moving towards the 5G era and many technological advances have been proposed, there seem to be significant limitations in the capability to efficiently and flexibly handle the massive amount of QoS/QoE-oriented data that will be exchanged in a future Big-Data-driven society along with the super-high data rate and almost zero latency requirements. Thus, wireless Tbit/s communications and the supporting backhaul network infrastructure are expected to become the main technology trend within the next ten years and beyond. Terahertz (THz) transmission as a wireless backhaul extension of the optical fiber is an important building block to close this gap and guarantee high-speed internet access everywhere beyond 5G. Moreover, the increasing number of mobile and fixed users in the private sector as well as in the industry and the service sector will require hundreds of Gbit/s in the communication to or between cell towers (backhaul) or between cell towers and remote radio heads (fronthaul). Furthermore, new challenging Tbit/s connectivity scenarios are becoming ever more relevant for systems beyond 5G, including: NLOS connectivity based on metasurfaces with the capability to dynamically reconfigure so to track slowly moving users and Ad hoc connectivity in fast moving network topologies, e.g., based on drones or V2X links. In such scenarios, apart from the high data rates in the order of Tbit/s other critical parameters are range, reliability, adaptability and agility.
Together with extraordinary promises, THz communications bring unique and novel challenges that require rethinking classic communications and networking mechanisms. The root cause for these challenges is the ultra-wideband and extremely directional nature of THz communications links. Other peculiarities of THz communications include signal and antenna design, channel, and interference modeling. The fundamentally different structure of the interference, due to narrow beams, calls for thorough investigation and detailed modelling of interference. In these propagation and channel modelling studies, the contributions of line-of-sight (LoS), non-line-of-sight (NLoS), reflected and scattered components, as well as molecular noise and the blocking probabilities inherent in such high frequency regimes need to be taken into account. Medium access control (MAC) and radio resource management (RRM) protocols now must operate with pencil beams and thus have to be based on completely new principles. Fast handover procedures need to include the time required for discovery, localization and tracking functionalities. The Tbits/s data rates create significant challenges for the transceiver processing including algorithm and architecture design as well as hardware implementation.
Motivated by the potential of THz technologies to transform the future of ICT, this workshop will reveal and discuss the critical technology gaps as well as the appropriate enablers, in terms of baseband processing RF frontend, channel models and waveforms, signals and coding, beam-patterns and medium access control schemes. Most importantly, this workshop aims to shed some light on the potential accelerators or showstoppers in the adoption of THz as a major 6G wireless technology.